Efficiency Enhancement of Octave-Bandwidth Traveling Wave Tubes by Use of Multistage Depressed Collectors

摘要

Small, three- and five-stage depressed collectors were evaluated in conjunction with a 4. 8 to 9.6-GHz TWT of 325- to 675-W power output and a beam of 0.5 microperv. The multistage depressed collector (MDC) performed well even though its design had been optimized for a TWT of identical design but considerably less output power. Despite large, fixed losses (rf losses, interception losses, and harmonic power generated losses), significant efficiency enhancement was demonstrated with both the three- and five-stage depressed collectors. At saturated rf power output, the improvement in the overall efficiency ranged from a factor of 2.5 to 3.0 for the three-stage collector and a factor of 3.0 to 3.5 for the five-stage collector.